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49 lines
1.6 KiB
C++
49 lines
1.6 KiB
C++
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#pragma once
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#include <vector>
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#include <Columns/ColumnString.h>
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namespace DB
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{
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template <typename Impl>
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struct MultiSearchFirstIndexImpl
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{
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using ResultType = UInt64;
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static constexpr bool is_using_hyperscan = false;
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/// Variable for understanding, if we used offsets for the output, most
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/// likely to determine whether the function returns ColumnVector of ColumnArray.
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static constexpr bool is_column_array = false;
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static auto getReturnType() { return std::make_shared<DataTypeNumber<ResultType>>(); }
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static void vectorConstant(
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const ColumnString::Chars & haystack_data,
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const ColumnString::Offsets & haystack_offsets,
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const std::vector<StringRef> & needles,
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PaddedPODArray<UInt64> & res,
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[[maybe_unused]] PaddedPODArray<UInt64> & offsets)
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{
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auto searcher = Impl::createMultiSearcherInBigHaystack(needles);
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const size_t haystack_string_size = haystack_offsets.size();
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res.resize(haystack_string_size);
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size_t iteration = 0;
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while (searcher.hasMoreToSearch())
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{
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size_t prev_offset = 0;
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for (size_t j = 0; j < haystack_string_size; ++j)
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{
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const auto * haystack = &haystack_data[prev_offset];
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const auto * haystack_end = haystack + haystack_offsets[j] - prev_offset - 1;
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/// hasMoreToSearch traverse needles in increasing order
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if (iteration == 0 || res[j] == 0)
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res[j] = searcher.searchOneFirstIndex(haystack, haystack_end);
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prev_offset = haystack_offsets[j];
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}
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++iteration;
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}
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}
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};
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}
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